Mountain Pass, was now attempting to destroy Lee's
immense supply train, which was packed near Williamsport, and not very
heavily guarded.

Kilpatrick desired no better work than to assist his brave comrade, and
he at once hastened down the main road, and soon joined Buford in the
work of destruction. These combined commands were making fearful havoc
in the Rebel commissary and quartermaster stores. Many wagons were
burned, and the whole train would have shared the same fate had not the
united infantry and cavalry of the enemy come down upon us in
overwhelming force. But we were not to be driven away very suddenly nor
cheaply. Long and desperately we contended with the accumulating forces,
until darkness came on, when we found ourselves completely enveloped by
the foe. Nothing but splendid generalship and true bravery on the part
of our officers and men saved us from capture and destruction. Some of
our number were made prisoners, but our losses were very small
considering the amount of depredations we had committed, and the great
danger to which we were exposed. As it was, the commands were
successfully withdrawn from their hazardous position, and through the
darkness of the night we crossed Antietam Creek, and bivouacked in
safety on the opposite bank. Several prisoners were captured from the
Rebels during the fights of the day. They were mostly from Alabama and
Louisiana regiments; and they state that their army is all together, and
well on its way to the river. They speak doubtfully of Lee's recrossing
the Potomac.

[Illustration: THE CAVALRY BIVOUAC.]

_July 7._--Our cavalry is in the vicinity of Boonsboro', and is acting
mostly on the defensive. The enemy in force is in our front, and an
attack is momentarily expected. At six P. M. "to horse" was sounded
throughout our camps; and, after waiting two hours in rain, ready for
a move, orders were received to return to our quarters. Rain is now
falling in torrents, accompanied with fearful thunderings and lightnings.
Unpleasant as it is, we welcome its peltings, hoping that the storm will
raise the Potomac above the fording mark, and thus give Meade an
opportunity to attack Lee before he has time to recross the river into
Virginia. We know that his pontoons at Falling Waters have been totally
destroyed by our cavalry and by the high water, and that the only ford
available is at Williamsport, and hence we welcome the falling floods.
Many of us have to lie down in wa